i agree, you need to keep him separate until he is better or you determine the cause of his behavior. He could have a head injury, or there are illnesses which effect muscle coordination. At this point, my best guess is head injury. Those can be very serious, but the fact that he is doing better today is very positive.
See if you can construct something for him to stay in for a while that will give him a little room. It's always good to have a "hospital" pen or hutch. Provide fresh water and food, maybe some mashed hard boiled eggs. Some chicken vitamins in the water would be good. Or you can give him a couple drops of Polyvisol baby vitamins without iron. Just be careful of his head and neck, in case there is an injury there. Many injuries heal on their own but take time, so he may need a week or two to fully recover.
Please keep us posted on his condition or if you observe any other symptoms. Hope he continues to get better.